Roller vane rotary pump



1, 25, 1949. H. H. LOOKE ROLLER VANE ROTARY PUMP Filed May 1, 1946 INVENTOR AQE Ni A a/my HANJE/V LOOAE Patented Jan. 25, 1949 ROLLER VANE ROTARY PUMP Harry Hansen Locke, Caulfleld, Victoria,

Austraua In Australia May 3, 1945 Application May 1, 1946, Serial No. 666,416

8 Claims. (Cl. 103-136) This invention relates to an improved rotary pump and refers especially to rotary pumps of the type wherein a rotor is eccentrically mounted within a casing having inlet and outlet ports communicating with feed and delivery pipes.

A rotary pump has previously been devised which comprises essentially a casing, a circular chamber in the casing, inlet and outlet ports communicating with the chamber, a rotor mounted eccentrically and rotatably in the chamber. a plurality of radial or approximately radial recesses in the rotor, a roller or cylindrical piston. in each recess, and a channel or channels in the leading face of each recess for admitting liquid under pressure to the recess in order to maintain the rollers or pistons in contact with the wall of the chamber when the rotor is rotated.

More specifically, the pump (which is described in the prior Australian Patent No. 121563) comprises a casing, a circular chamber in the casing,

- inlet and outlet ports in the casing and communicating with the chamber, said inlet and outlet ports being substantially diametrically opposite to one another, acylindrical rotor mounted eccentrically in the chamber and arranged so as to be contiguous with or close to the peripheral wall of the chamber at a point between the inlet and outlet ports, the point of greatest radial distance between the periphery of the rotor and the peripheral wall of the chamber being located substantially midway between the inlet and outlet ports on the opposite side of the chamber from the point at which the rotor is closest to the peripheral wall of the chamber, a plurality of radial or approximately radial recesses in the rotor, a cylindrical roller fitting neatly within each recess and rotatable and radially movable therein, the diameter of each roller being at least twice the maximum distance between the rotor and the peripheral wall of the chamber and the depth of each recess being slightly greater than the diameter of a roller, and a channel or chan nels in the leading face of each recess to admit liquid under pressure to the inner end of the recess and thereby assist in maintaining the rollers in contact with the wall of the chamber;

The liquid under pressure in'th'e portion of the crescent-shaped space between a roller and the outlet port is admitted through the channel or channels to the inner'end of the recess in which the roller is fitted and exerts an outward radial pressure on the inner periphery of the roller which exceeds the inward radial pressure of the liquid against the outer periphery of the roller,

thereby assisting to maintain the roller in contact with the peripheral wall of the chamber.,

Rotary pumps of the type above described are subject to certain disadvantages. In. the first place, after the leading edge of a recess moves past the point on the inner periphery of the casing at which the rotor is closest to the periphery'of the casing (hereinafter termed the midpoint), the said leading edge moves away from the periphery and until the following edge of the recess reaches the mid-point the eifectiveness of the seal between the inlet and outlet chambers is greatly reduced.

When the recess reaches the outlet port, the pressure on both sides of the roller is equalised and the roller is maintained against the casing by centrifugal force. However, when the roller reaches the end of the outlet port nearest the mid-point, the roller is forced into the recess in the rotor by the pressure of liquid, and thus ceases to create an efiective seal between the rotor and the casing. The roller remains in this position until the following edge of its recess reaches the mid-point, thereby sealing off the recess from the outlet chamber of the pump and thus relieving the pressure on the outer face of the roller. This causes the roller to be suddenly thrownoutwards against the wall of the casing by centrifugal force, which results in undesirable noise and wear.

It is an object of this invention to provide improvements in a rotary pump of the kind de-. scribed which will substantially overcome the abovementioned disadvantages and will enable the construction of a pump which is economical to build and is thoroughly efllcient in operation.

A feature of the invention consists in providing an arcuate recess in the peripheral wall of the casing at or adjacent to the point of closest approach at'which the rotor is closest to the periphery of the rotor chamber, the curvature of such recess being substantially equivalent to that of the rotor and the latter being mounted in the casing so that its periphery rotates in fluid-tight running contact with the periphery of such recess.

, tamer-towards the point of closest approach from I the centre of curvature of the internal periphery of the casing, and the length of said recess being greater than the distance between the leading and following edges of each recess in the rotor.

The centre of curvature of the arcuate recess is preferably coincidental with the centre of the rotor shaft so that both the leading and following edges of the recesses in the rotor are in contact with or in close proximity to the periphery of the casing over the full length of the said recess.

A further feature of the invention resides in the provision of means for admitting fluid under pressure to the inner face of each roller when the latter is in the region of the point of closest approach, and preferably when the roller is approaching the point of closest approach, whereby the roller will be forced outwards against the periphery of the casing by such fluid pressure and by centrifugal force so as to assist in maintaining theseal between the inlet and outlet chambers of the pump. This means may comprise a port, channel or groove in the end of the casing or in the end-plate and disposed so as to place the channel in the leading face of the recess and/or the space between the leading edge of the recess and the roller in communication with the outlet chamber of the pump when the roller is in the vicinity of or approaching the point of closest approach.

The rotor may be provided with two, three or any other appropriate number of rollers and recesses therefor, although three are preferred. The ports or channels for ingress and egress of fluid to and from the rotor chamber may be formed in one or both ends of the casing.

Other objects and features of the invention will become apparent from the ensuing description of the form of the invention illustrated in the accompanying drawings, wherein:

Figure 1 is a view in end elevation of a rotary pump constructed in accordance with the invention, an end plate having been removed.

Figure 2 is a view in side elevation partly in section taken on the line 2-2 of Figure 1.

Figure 3 is a view in end elevation of the rotor.

Figure 4 is a view in section on the line 4-4 of Figure 3.

Figure 5 is a view of one of the rollers.

Figure 6 is a view in end elevation of the casing,

the rotor and rollers having been removed.

Figure 7 is a view in section taken on the line 1-'I of Figure 6. Y

Figures 8 and 9 are views of the pump showing the rotor in successive positions, and

Figure 10 is a diagrammatic view to an enlarged scale of the upper end of the casing.

Referring to the drawings, wherein the same reference numerals indicate like or corresponding parts, the reference numeral 23 indicatcsthe cylindrical casing of a rotary pump. The casing is provided with open ends which are adapted to be closed by end plates 2i, 22 secured to the casing 20 by bolts 23. The casing III is supported on a stand 24 and is furnished with inlet and outlet chambers formed in bosses 25, 26 disposed on opposite sides of the casing and integral therewith. Flanges 21 are provided on the bosses 25, 26 for attachment of inlet and outlet pipes thereto.

The inlet chamber communicates through ports 28 in the casing 20 with chambers 23 in the end plates 2i, 22 and thence through inlet ports 3|, 3| with the interior of the casing 23. The outlet chamber connects through ports 32 in the casing III with chambers 33 in the end plates, and the chambers 33 communicate through outlet ports 34, 35 with the interior of the casing.

A rotor 36 is eccentrically and rotatably mounted within the casing 23. The rotor 33 is keyed iii 4 to a shaft 31 which is carried in ball bearings 38 mounted in the end plates II, 22. The bearlugs 38 are retained in position by cover plates 33. Rotation is imparted to the shaft by any suitable source of power not shown). Suitable gland means not shown) are provided to prevent leak- :ze of fluid between the bearings and the shaft The casing 20 can be of any approved width and diameter and the clearance between the ends of the rotor 33 and the ends of the casing 20 is just sufficient to permit freedom of rotation of the rotor 33 within the rotor chamber,

Three equally spaced radial recesses. are formed in the rotor 33 in which rollers ll are fitted, the said rollers being cylindrical in shape and being capable of radial movement in the re cesses 40. The inner ends of the recesses 43 are semi-cylindrical to accommodate the rollers II when they are in their innermost positions. Channels 42 are formed in the leading and inner faces of the recesses 43 at each side of each recess 40 (see Figure 4). The channels I! are in communlcation with arcuate ports 43 in the rotor 30 on each end thereof, the said ports 43 extending in opposite directions from the inner ends of the recesses Iii.

An arcuate recess 44 (see Figure 10) is formed in the periphery of the casing 2| at the upper end thereof adjacent to the point at which the rotor 36 is closest to the said periphery. The recess 44 extends from point X to point Y on the casing as shown in Figure 10, and is of the same curvature as that of the rotor 33. The shaft 31 is so mounted in the casing 2| that the periphery of the rotor 36 moves in fluid tight running contact with the peripheral wall of the recess II from Y to X, (the direction of rotation being as shown in Figure l). The length of the recess ll, that is the distance from x to Y. is greater than the width of one of the recesses 43, so that the following edge 45 of one of said recesses 43 enters the recess ll before the leading edge I. has left the recess ll. Thus, even if the roller H is not in contact with the periphery of the casing at this point, an effective seal is created between the rotor 36 and the periphery of the casing 33 in the vicinity of the point of closest approach. a

This seal is rendered more eflective owing to the means employed (as. hereinafter described) for causing the rollers II to be moved outwardly against the periphery of the casing 30 as they approach the point of closest approach.

The outer inlet ports 30 are disposed adjacent to the periphery of the rotor chamber and are shaped to increase in width from their upper or rear ends to their lower or forward ends. The inner inlet ports 3i are adapted to communicate with the inner ends of the recesses 43 in the rotor as the said recesses pass thereover, and the said ports 3| are located so that their upper or rear ends are brought into communication with a recess 40 when the leading edge of said recess ll has passed the end X of the arcuate recess M and so that their lower or forward ends are cut oif from communication with the recess ll when the lower or forward ends of the outer inlet ports 33 are closed by the roller ll in the said recess.

The said outer inlet ports 33 are shaped so as not to substantially exceed in radial extent the crescent-shaped recess between the rotor and the periphery of the casing 20, so that the said ports are closed by the rollers II as they pass thereover. Fluid is thus admitted to the rotor chamber in advance of the rollers 4| but the ports 33 are closed by: the rollers 4| before the :outlet ports are in communication- -with-- .the corresponding recesses 40.

-- The outer outlet ports 35 are located adjacent.

with the inner ends of the recesses 40 in the rotor until shortly after the following edge of the recess 40 enters the arcuate recess 44 .and are cut oil! from communication with the recess 40 shortly before the leading edge of the recess 40 leaves the arcuate recess 44. I

Thus fluid underpressure is admitted to the inner ends of the recesses 40 over a maximum angular distance, and thereby .assists in maintaining the rollers 4i against the peripheral wall of the casing during rotation of'the rotor 36.

The successive positions. of the rollers 4| and recesses 50 during rotation of the rotor are shown at A, B and C in Figures 1, 8-and 9.' In Figure 1 the 'roller in, position A is at the point of closest approach and is functionin to seal the outlet from the .inlet, at this point. The seal is also effected by the leading and following edges 46, 45 of the recess in in this position being in contact with or in close proximity to the periphery of the casing between the points X and Y (see Figure When the roller 4! reaches position A in Figure 8, fluid is admitted to the'recess 40 through the inlet ports and 3i and, at the same time, the roller commences to move outwardly in the recess due to centrifugal force acting thereon and to the divergence between the periphery of the rotor and the periphery of the casing. The fluid admitted through the inlet ports 30, 3| is moved around ahead of the roller 4| by such roller and when the roller reaches position B' in Figure 1, the inlet ports 30, 3| are'cut off from the recess 40, so that a positive transfer to the outlet ports of the fluid admitted through the inlet ports is effected.

At position B in Figure 8, the inner end of the recess 40 is in communication with the inner outlet port 34 so that pressure is applied to the inner face of the roller to maintain it against the periphery of the casing. Egress of fluid through the outlet ports 34 and 35 occurs owing to the fluid in front of the roller being forcedoutwardly through said outlet ports as the roller moves from position B in Figure 1 to position C in Figure 9. The outlet port 34 remains in communication with the inner end of the recess. 40 after the leading edge 66 of such recess enters the arcuate recess 44 and is cut off therefrom shortly before the side leading edge 46 leaves the arcuate recess 44, so that fluid pressure acts on the inner face of the roller until after it passes the point of closest approach.

It will be understood that the pump may be constructed so that the point of closest approach, that is the point at which the rotor is closest to the peripheral wall ofthe chamber is located at the top or bottom or at either side oftthe pump when the latter is erected in its running position.

In the specification and claims hereof the midpoint? of the peripheral wall'ofthe rotor chamber the said wall. I

It will'also be appreciated that end plates may be provided atone or both ends of the casing,

and that the shaft may be supported in bearings at one end only of the casing instead of at both ends thereof.

I claim:

1. A rotary pump comprising a casing, a circular rotor chamber in the casing, inlet. and outlet ports in the casing communicating with the rotor chamber, a rotor eccentrically and rotatably mounted in the rotor chamber, radial recesses in the rotor, each of said radial recesses having a leading edge and. a following edge, rollers fitted in the radial recesses and capable of radial movement therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber, the curvature of said arcuate recess being substantially equal to that of the periphery of the rotor and the said rotor being in fluid-tight running contact with the peripheral wall of said arcuate recess, the width of the arcuate recess being substantially equal to that of the rotor chamber and the centres of curvature of the arcuate recess and the rotor being coincidental, the length of the arcuate recess being greater than the distance between the leading and the following edges of a radial recess, and the outlet port being in communication with the inner end of each radial recess as it approaches the said point of closest approach and remaining in communication with said radial recess until shortly before the leading edge of said radial recess leaves the said arcuate recess.

2. A rotary pump comprising a casing, a circular rotor chamber in the casing, inlet and outlet ports in the casing communicating with the rotor chamber, a rotor eccentrically and rotatably mounted in the rotor chamber, radial recesses in the rotor, each of said radial recesses having a leading edge and a following edge, rollers fitted in the radial recesses and capable of radial movement therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber, the curvature of said arcuate recess being substantially equal to that of the periphery of the rotor and .the said rotor being in fluid tight running contact with the peripheral wall of said arcuate recess, the centre of curvature of the arcuate recess being coincidental with that of the rotor, and the length of the arcuate recess being greater than the distance between the leading and following edges of a radial recess in the rotor, and the outlet port being in communication with the inner end of each radial recess until after the following edge of the radial recess has entered the arcuate recess and being cut off from communication with the said inner end before the leading edge of the radial recess leaves the arcuate recess.

3. A rotary pump comprising a casing, a circular rotor chamber in the casing, inlet and outlet ports in the casing communicating with the rotor chamber, a rotor eccentrically and rotatably mounted in the rotor chamber, radial recesses in the rotor, each of said radial recesses having a leading edge and a following edge, rollers fitted in the radial recesses and capable of radial ---movement therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber. the curvature of said arcuate recess being substantially equal to that of the periphery of the rotor and the said rotor being in fluid tight running contact with the peripheral wall of said arcuate recess, the width of the arcuate recess being substantially equal to that of the rotor chamber and the centres of curvature of the arcuate recess and the rotor being coincidental, the length of the arcuate recess being greater than the distance between the leading and following edges of a radial recess, the outlet port being in communication with the inner end of each radial recess until after the following edge of theradial recess has entered the arcuate recess and being cut oi! from communication with the said inner end before the leading edge 01' the radial recess leaves the arcuate recess, and the inlet port being in communication with each radial recess in the rotor shortly after the leading edge of such radial recess leaves the arcuate recess in the casing.

4. A rotary pump comprising a casing, a circular rotor chamber in the casing, inlet and outlet ports in the casing communicating with the rotor chamber, a rotor eccentrically and rotataably mounted in the rotor chamber, radial recesses in the rotor, each of said radial recesses having a leading edge and a following edge, rollers fitted in the radial recesses and capable of radial movement'therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber, the curvature of said arcuate recess being substantially equal to that of the periphery of the rotor and the said rotor being in fluid tight running contact with the peripheral wall of saidarcuate recess, the width of the arcuate recess being substantially equal to that of the rotor chamber and the centres of curvature of the arcuate recess and the rotor being coincidental, the length of the arcuate recess being greater than the distance between the leading and following edges of a radial recess, the outlet port being in communication with the inner end of each radial recess until after the following edge of the radial recess has entered the arcuate recess and being cut oil from communication with the said inner end before the leading edge of the radial recess leaves the arcuate recess, the inlet port being in communication with each radial recess in the rotor shortly after the leading edge of such radial recess leaves the arcuate recess in the casing, and the outlet port being in communication with the inner end of each radial recess in the rotor shortly after the said radial recess is out off from communication with the inlet port.

5. A rotary pump comprising a casing, a circular rotor chamber in the casing, a rotor eccentrically and rotatably mounted in the rotor chamber, radial recesses in the rotor, each of said radial recesses having a leading edge and a following edge, rollers fitted in the radial recesses and capable of radial movement therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber, the curvature of said arcuate recess being substantially equal to that of the periphery of the rotor and thesaid rotor being in fluid tight running contact with the peripheral wall of said arcuate recess, the width of the arcuate recess being substantially equal to that of the rotor chamber and the centres of curvature of the arcuaterecessandtherotorbelngcoinddentnlthe length of the arcuate recess being greater than the distance between the leading and following edges of a radial recess, inner and outer inlet ports in the end of the casing, and inner and outer outlet ports in the end of the casing, the forward end of the inner outlet port communieating with the inner end of each radial recess until the following edge of said radial recess has entered the arcuate recess and being cut of! from communication with the said inner endof said radial recess before the leading edge of said radial recess leaves the arcuate recess.

6. A rotary pump comprising a casing, a cir-,

cular rotor chamber in the casing. a rotor eccentrically and rotatably mounted in the rotor chamber, radial recesses in the rotor. each of said radial recesses having a leading edge and a following edge, channels formed in the leading and inner faces of the radial recesses. rollers fitted in the radial recesses and capable of radial movement therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber, the curvature of said arcuate recess being substantially equal to that of the periphery of the rotor and the said rotor being in fluid tight running contact with the peripheral wall of said arcuate recess. the width of the arcuate recess being substantially equal to that of the rotor chamber and the centres of curvature of the arcuate recess and the rotor being coincidental, the length of the arcuate recess being greater than the distance between the leading and following edges of a radial recess, innerand outer inlet ports in the end of the easing and inner and outer outlet ports in the end of the casing. the forward end of the inner outlet port communicating with the inner end of each radial recess until the following edge or said rsdial recess has entered the arcuate recess and being cut of! from communication with the said inner end of said radial recess before the leading edge of said radial recess leaves the arcuate recess,

and the rear end of the inner outlet port communicating with the inner end of each radial recess shortly after the latter is cut off from communication with the inlet ports.

7. A rotary pump comprising a casing, a circular rotor chamber in the casing, a rotor eccentrically and rotatably mounted in the rotor chamber, radial recesses in the rotor, each of said radial recesses having a leading edge and a following edge, rollers fitted in the radial recesses and capable of radial movement therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber, the curvature of said arcuate recess being substantially equal to that of the periphery of the rotor and the said rotor being in fluid tight running contact with the peripheral wall of said arcuate recess, the width of the arcuate recess being substantially equal to that of the rotor chamber and the centres of curvature of the arouate recess and the rotor being coincidental, the length of the arcuate recess being greater than the distance between the leading and following edges of a radial recess, inner and outer inlet ports in the end of the casing, and inner and outer outlet ports in the end of the casing, the outer inlet port not substantially exceeding in radial extent that of the crescent-shaped space betwen the rotor and the periphery of the casing, the outer outlet port being adjacent to the periphend of each radial recess until shortly before the leading edge of said radial recess leaves the arouate recess.

8. A rotary pump comprising a, casing, a circular rotor chamber in the casing, a rotor eccentrically and rotatably mounted in the rotor chambe'r, radial recesses in the rotor, each of said radial recesses having a leading edge and a following edge, rollers fitted in the radial recesses and capable of radial movement therein, an arcuate recess in the periphery of the rotor chamber adjacent to the point of closest approach at which the rotor is closest to the periphery of the rotor chamber, the curvature of said arcuate recess being substantially equal to that of the periph- "ery of the rotor and the said rotor being in fluid tight running contact with the peripheral wall of said arcuate recess, the width of the arcuate' recess being substantially equal to that of the rotor chamber and the centres of curvature of the armate recess and the rotor being coincidental, the length of thearcuate recess being greater than the distance between the leading and following edgeslof a radial recess, inner and outer inlet ports in the end of the casing and inner and outer outlet ports in the end of the casing, the forward end of the inner outlet port communicating with 10 the inner end of each radial recess until the following edge of said radial recess has entered the arcuate recess and is cut of! from communication with the radial recess before the leading edge of said radial recess leaves the arcuate recess, the outer inlet port not substantially exceeding in radial extent that of the crescent-shaped space between the rotor and the periphery of the casing, the outer outlet port being adjacent to the periph cry of the casing, and the forward end of the inner outlet port communicating with the inner end of each radial recess until shortly before the leading edge of said radical recess leaves the arouate recess, and the rear end of the inner outlet port communicating with the inner end of each radial recess shortly after the latter is cut oil from communication with the inlet ports.

' HARRY HANSEN LOOKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

